What is a Process?

A process is a single executable module that runs concurrently with other executable modules. For example, in a multi-tasking environment that supports processes, like OS/2, a word processor, an Internet browser, and a database, are separate processes and can run concurrently. 

Processes are separate executable, loadable modules as opposed to threads, which are not loadable. Multiple threads of execution may occur within a process. For example, from within a data base application, a user may start both a spell check and a time consuming sort. In order to continue to accept further input from the user, the active thread could start two other concurrent threads of execution, one for the spell check and one for the sort. Contrast this with multiple .EXE files (processes) like a word processor, a database, and Internet browser, multi-tasking under OS/2 for example.